RIYADH — Saudi King Abdullah announced on Sunday he was giving women the right to vote and run in municipal elections, the only public polls in the ultra-conservative Gulf kingdom.

He also announced that women would have the right to join the all-appointed Shura (consultative) Council, in an address opening a new term of the council.

"Starting with the next term, women will have the right to run in municipal elections and to choose candidates, according to Islamic principles," he said.

This means that women will be able to take part in the elections that will be held in four years, as the next vote is due to take place on Thursday and nominations for those are already in.

"We have decided that women will participate in the Shura Council as members starting the next term," the king also said in an unexpected move to enfranchise women in the ultra-conservative kingdom.

"The Muslim woman... must not be marginalised in opinion or advice," said King Abdullah.

More than 5,000 men will compete in Thursday's municipal elections, only the second in Saudi Arabia's history, to fill half the seats in the kingdom's 285 municipal councils. The other half are appointed by the government.

The first elections were held in 2005, but the government extended the existing councils' term for two years.

More than 60 intellectuals and activists called in May for a boycott of the ballot because "municipal councils lack the authority to effectively carry out their role" and "half of their members are appointed," as well as because they exclude women.

Saudi Arabia's Shura Council had recommended allowing women to vote in the next local polls, officials have said.

In April, Samar Badawi said she was suing the municipal affairs ministry for upholding the ban on women taking part in the local poll.

Badawi filed a lawsuit at the administrative court in Mecca against the ministry for denying women the right to register as voters.

Also in April, a group of women defied the ban on women in elections by turning up at a voter registration office in the Red Sea city of Jeddah, in a rare public demonstration against the male-only electoral system.

But they were turned back by the head of the centre who told them women were still banned from voting.

Women's rights activists have long fought to gain the right to vote in the kingdom that applies a strict version of Sunni Islam and bans women from driving or travelling without the consent of a male guardian.

A group of defiant Saudi women got behind the steering wheels of their cars on June 17 in response to calls for nationwide action against the ban.

US Secretary of State Hillary Clinton has publicly thrown her support behind the campaign, saying that "what these women are doing is brave, and what they are seeking is right."

The icon of the campaign is Manal al-Sharif, a 32-year-old computer security consultant who was arrested on May 22 and detained for 10 days after posting on YouTube a video of herself driving around the eastern city of Khobar.

In July, 14 US women senators pressed King Abdullah in a letter to lift the ban on women drivers.

Women in the kingdom must hire drivers, or depend on the goodwill of male relatives if they do not have the means.